Reuse of faeces and urine from ecological sanitation
Practical Action
Treatment
Treatment processes are relatively similar to those for faeces, but the inclusion of urine
makes the systems less dry and therefore less susceptible to treatment from reduced moisture
content. The process mostly involves competition with other organisms (within the soil or
added material) and increased temperature. Secondary treatment typically takes place by
leaving the waste in the ground and using an alternate pit. Some methodologies will then
remove the waste from the pit after a set period of time (long enough to allow pathogens to
die off - approximately 1-2 years in tropical conditions), whilst others simply use the nutrients
by planting a tree directly onto the pit once it becomes full.
Application and storage advice
In application and storage mixed urine and faeces should be treated the same as separated
faeces.
General guidance on application
Alongside the points above there are some more general recommendations (Schönning and
Stenström, 2004):
urine diversion is generally recommended;
twin pit collection within in a sealed vault is preferable;
every effort should be taken to reduce faecal contamination of diverted urine;
solar heating can increase die-off of pathogens;
toilet paper should be collected separately unless composting or incineration are the
intended treatment processes;
anal cleansing material should not be collected with urine;
stones used for anal cleansing should be collected separately, vegetable material
used for this purpose can be added to the faeces compartment;
contents of nappies/diapers should be emptied into the faecal compartment;
other material such as sanitary napkins should only go into the faecal compartment if
they are degradable, otherwise they should be treated as solid waste; and
if diarrhoea is prevalent extra absorbent material may have to be added.
Conclusion
There are clearly many important considerations for householders when using ecological
sanitation. This technical brief has described the main treatment methods and application
techniques, wherever possible the following control measures should all be practiced (WHO,
2006):
treatment of excreta;
crop restriction (e.g. only applying material to crops that are either non-food crops or
require cooking before eating).
practice recommended excreta handling and application techniques;
allow recommended time between fertilising and harvesting/consumption;
practice appropriate food preparation (e.g. peeling, washing and cooking); and
restrict exposure to excreta and implement hygiene education.
The WHO guidance notes on this topic have recently been revised and provide excellent
guidance on the topic (WHO, 2006), as do publications by Schönning and Stenström (2004)
and Jönsson et al (2004).
The benefits of ecological sanitation are potentially high, following these guidelines will assist
in ensuring that these benefits are achieved safely and hygienically. It is worth bearing in
mind the barriers illustrated in figure 1 and ensuring that communities practice all possible
initiatives to reduce the risk of faecal-oral disease. Simple hand washing devices are detailed
in Morgan (2007) that could be installed near to ecosan facilities and other toilets, they
should also be adopted for use by those applying material from ecosan facilities to fields.
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